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Monday, June 23, 2014

Mystery island’ on Saturnmoon’s methane sea puzzles scientists

Ligeia Mare, shown here in a
false-color image from NASA's Cassini mission, is the second largest known body
of liquid on Saturn's moon Titan (Image from nasa.gov)

A strange object, dubbed a “mystery island,” has
appeared briefly on images of a methane sea on Saturn’s largest moon, Titan.
Studying the images, taken by the spacecraft Cassini, astronomers came up with
four possible explanations.

The unusual discovery was made on Ligeia Mare, the
second-largest of Titan’s three bodies of liquid big enough to be considered
seas. A bright white object was spotted off the rocky southern coast of the sea
when Cassini flew by it on July 10, 2013. Neither earlier pictures taken by the
spacecraft’s radar nor the one taken on July 26 have the object, which means
the scientists spotted a big transient process on the usually calm body.

“This discovery tells us that the liquids in Titan's
northern hemisphere are not simply stagnant and unchanging, but rather that
changes do occur,” said Jason
Hofgartner, lead author of a paper describing the discovery, which was
published on Sunday in Nature Geoscience magazine.

Earlier studies of Ligeia Mare based on Cassini images
showed that the surface of the sea, which consists of methane and ethane, is
remarkably flat within several millimeters. One of the possible explanations of
what the “mysterious island” could have been implies that this may be changing.

Cassini images of Ligeia Mare taken in April 2007
(top) and July 2013 (bottom) with the "mysterious island" marked.
Images by NASA

Titan has seasons just like Earth does, and is
currently transitioning from the vernal equinox, which happened in August 2009,
to summer solstice that will be in full swing in May 2017. The northern
hemisphere of the moon is heating up, and this energy could be causing waves,
one of which could have been shot by Cassini, authors of the study speculate.
If true, this would be the first image of waves taken on Titan.

Other possible explanations are that the object was
actually bubbles bursting from the seabed, a methane iceberg that formed during
winter and remained submerged until the liquid became warmer, or some suspended
solids akin to slit on earth that formed an actual island that was washed away
later.

Among Saturn’s 62 moons Titan is the largest and
arguably most interesting scientifically. It’s the only moon in the Solar
system that has its own dense atmosphere consisting of methane and nitrogen.
It’s also the only one proven to have surface liquids, although at temperatures
on the surface around -180 degrees Celsius, those liquids are hydrocarbons that
are in gas phase in earth conditions.

NASA considered sending a floating robot to Titan to
study its environment up and close, but eventually opted for a Mars mission. An
alternative mission would involve a balloon mapping Titan’s surface.

MUFON

Stabilize the camera on a tripod. If there is no tripod, then set it on top of a stable, flat surface. If that is not possible lean against a wall to stabilize your body and prevent the camera from filming in a shaky, unsteady manner.

Provide visual reference points for comparison. This includes the horizon, treetops, lampposts, houses, and geographical landmarks (i.e., Horsetooth Reservoir, Mt. Adams, etc.) Provide this in the video whenever is appropriate and doesn’t detract from what your focus is, the UFO.

Narrate your videotape. Provide details of the date, time, location, and direction (N,S,E,W) you are looking in. Provide your observations on the weather, including approximate temperature, windspeed, any visible cloud cover or noticeable weather anomalies or events. Narrate on the shape, size, color, movements, approximate altitude of the UFO, etc and what it appears to be doing. Also include any unusual physical, psychological or emotional sensations you might have. Narrate any visual reference points on camera so they correlate with what the viewer will see, and thereby will be better able to understand.

Be persistent and consistent. Return to the scene to videotape and record at this same location. If you have been successful once, the UFO sightings may be occurring in this region regularly, perhaps for specific reasons unknown, and you may be successful again. You may also wish to return to the same location at a different time of day (daylight hours) for better orientation and reference. Film just a minute or two under “normal” circumstances for comparison. Write down what you remember immediately after. As soon as you are done recording the experience/event, immediately write down your impressions, memories, thoughts, emotions, etc. so it is on the record in writing. If there were other witnesses, have them independently record their own impressions, thoughts, etc. Include in this exercise any drawings, sketches, or diagrams. Make sure you date and sign your documentation.

Always be prepared. Have a digital camera or better yet a video camera with you, charged and ready to go, at all times. Make sure you know how to use your camera (and your cell phone video/photo camera) quickly and properly. These events can occur suddenly, unexpectedly, and often quite randomly, so you will need to be prepared.